android中嵌套的ExpandableListView中没有可见的子级

我正在尝试创建一个嵌套的

可扩展列表

（3层）。但使用以下代码，子类别列表（第三层）不可见

getChildCount>1

但是

getChildview

从未在

SecondLevelAdapter

中调用

-> menu
    -> Category
        -> sub category

数据结构：

类菜单{
列出类别；
}
类别{
列出子类别；
}
公共类ParentLevelAdapter扩展了BaseExpandableListAdapter{
私有最终上下文mContext；
私有最终列表mListDataHeader；
公共ParentLevelAdapter（上下文mContext，列表mListDataHeader）{
this.mContext=mContext；
this.mListDataHeader=mListDataHeader；
}
@凌驾
公共导航类别getChild（int-groupPosition，int-childPosition）{
返回mListDataHeader.get（groupPosition）.categories.get（childPosition）；
}
@凌驾
公共长getChildId（int-groupPosition，int-childPosition）{
返回子位置；
}
@凌驾
公共视图getChildView（int-groupPosition、int-childPosition、，
布尔值isLastChild、视图转换视图、视图组父级）{
final ExpandableListView secondLevelExpListView=新的ExpandableListView（this.mContext）；
setAdapter（新的SecondLevelAdapter（this.mContext，getChild（groupPosition，childPosition））；
返回secondLevelExpListView；
}
@凌驾
公共整数getChildrenCount（整数组位置）{
返回mListDataHeader.get（groupPosition.categories.size（）；
}
@凌驾
公共导航菜单getGroup（int groupPosition）{
返回此.mListDataHeader.get（groupPosition）；
}
@凌驾
public int getGroupCount（）{
返回此.mListDataHeader.size（）；
}
@凌驾
公共长getGroupId（int-groupPosition）{
返回组位置；
}
类视图持有者{
图像视图图标；
文本视图名称；
}
@凌驾
公共视图getGroupView（int-groupPosition，布尔值isExpanded，
视图（视图、视图组父级）{
视窗座；
if（convertView==null）{
LayoutInflater LayoutInflater=（LayoutInflater）this.mContext
.getSystemService（上下文布局\充气机\服务）；
convertView=LayoutFlater.充气（R.layout.nav_菜单项_视图，父项，false）；
holder=新的ViewHolder（）；
holder.icon=（ImageView）convertView.findViewById（R.id.icon）；
holder.name=（TextView）convertView.findViewById（R.id.menu\u name）；
convertView.setTag（支架）；
}
否则{
holder=（ViewHolder）convertView.getTag（）；
}
holder.name.setText（getGroup（groupPosition.name）；
holder.icon.setImageResource（getGroup（groupPosition）.iconResolutionId）；
返回视图；
}
@凌驾
公共布尔表ID（）{
返回true；
}
@凌驾
公共布尔值isChildSelectable（int-groupPosition，int-childPosition）{
返回true；
}
}
公共类SecondLevelAdapter扩展了BaseExpandableListAdapter{
私有最终上下文mContext；
私有最终列表mListDataHeader；
私人最终导航类别导航类别；
public SecondLevelAdapter（上下文mContext、导航类别NavCategory）{
this.mContext=mContext；
this.mListDataHeader=navCategory.sub_categories；
this.navCategory=navCategory；
}
@凌驾
公共导航子类别getChild（int-groupPosition，int-childPosition）{//忽略组
返回mListDataHeader.get（childPosition）；
}
@凌驾
公共长getChildId（int-groupPosition，int-childPosition）{
返回子位置；
}
@凌驾
公共布尔表ID（）{
返回false；
}
类子视图持有者{
文本视图名称；
}
类GroupViewHolder{
文本视图名称；
}
@凌驾
公共视图getChildView（int-groupPosition、int-childPosition、，
布尔值isLastChild、视图转换视图、视图组父级）{
儿童视窗座；
if（convertView==null）{
LayoutInflater LayoutInflater=（LayoutInflater）this.mContext
.getSystemService（上下文布局\充气机\服务）；
convertView=LayoutFlater.充气（R.layout.nav_菜单第二项，父项，false）；
holder=新的ChildViewHolder（）；
holder.name=（TextView）convertView.findViewById（R.id.menu\u name）；
convertView.setTag（支架）；
}
否则{
holder=（ChildViewHolder）convertView.getTag（）；
}
holder.name.setText（getChild（groupPosition，childPosition）.sub_category_name）；
返回视图；
}
@凌驾
公共布尔值isChildSelectable（int-groupPosition，int-childPosition）{
返回false；
}
@凌驾
公共整数getChildrenCount（整数组位置）{
返回mListDataHeader.size（）；
}
@凌驾
公共导航类别getGroup（int groupPosition）{
返回导航类别；
}
@凌驾
public int getGroupCount（）{
返回1；
}
@凌驾
公共长getGroupId（int-groupPosition）{
返回组位置；
}
@凌驾
公共视图getGroupView（int-groupPosition，布尔值isExpanded，
视图（视图、视图组父级）{
GroupViewHolder GroupViewHolder；
if（convertView==null）{
LayoutInflater LayoutInflater=（LayoutInflater）this.mContext
.getSystemService（上下文布局\充气机\服务）；
convertView=LayoutFlater.充气（R.layout.nav_菜单第二组项，父项，false）；
groupViewHolder=新的groupViewHolder（）；
groupViewHolder.name=（TextView）convertView.findViewById（R.id.menu_name）；
convertView.se
class Menu{
    List<Category> categories;
}

class Category{
    List<SubCategory> subcategories;
}

public class ParentLevelAdapter extends BaseExpandableListAdapter {
    private final Context mContext;
    private final List<NavigationMenu> mListDataHeader;

    public ParentLevelAdapter(Context mContext, List<NavigationMenu> mListDataHeader) {
        this.mContext = mContext;
        this.mListDataHeader = mListDataHeader;
    }

    @Override
    public NavCategory getChild(int groupPosition, int childPosition) {
        return mListDataHeader.get(groupPosition).categories.get(childPosition);
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition,
                             boolean isLastChild, View convertView, ViewGroup parent) {
        final ExpandableListView secondLevelExpListView = new ExpandableListView(this.mContext);
        secondLevelExpListView.setAdapter(new SecondLevelAdapter(this.mContext, getChild(groupPosition,childPosition)));
        return secondLevelExpListView;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return mListDataHeader.get(groupPosition).categories.size();
    }

    @Override
    public NavigationMenu getGroup(int groupPosition) {
        return this.mListDataHeader.get(groupPosition);
    }

    @Override
    public int getGroupCount() {
        return this.mListDataHeader.size();
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    class ViewHolder{
        ImageView icon;
        TextView name;
    }
    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
                             View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            LayoutInflater layoutInflater = (LayoutInflater) this.mContext
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = layoutInflater.inflate(R.layout.nav_menu_item_view, parent, false);
            holder = new ViewHolder();
            holder.icon = (ImageView) convertView.findViewById(R.id.icon);
            holder.name = (TextView) convertView.findViewById(R.id.menu_name);
            convertView.setTag(holder);
        }
        else{
            holder = (ViewHolder) convertView.getTag();
        }
        holder.name.setText(getGroup(groupPosition).name);
        holder.icon.setImageResource(getGroup(groupPosition).iconResoluteID);
        return convertView;
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }
}

public class SecondLevelAdapter extends BaseExpandableListAdapter {
    private final Context mContext;
    private final List<NavSubcategory> mListDataHeader;
    private final NavCategory navCategory;

    public SecondLevelAdapter(Context mContext, NavCategory navCategory) {
        this.mContext = mContext;
        this.mListDataHeader = navCategory.sub_categories;
        this.navCategory = navCategory;
    }

    @Override
    public NavSubcategory getChild(int groupPosition, int childPosition) { //ignore group
        return mListDataHeader.get(childPosition);
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    class ChildViewHolder{
        TextView name;
    }

    class GroupViewHolder{
        TextView name;
    }


    @Override
    public View getChildView(int groupPosition, int childPosition,
                             boolean isLastChild, View convertView, ViewGroup parent) {
        ChildViewHolder holder;
        if (convertView == null) {
            LayoutInflater layoutInflater = (LayoutInflater) this.mContext
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = layoutInflater.inflate(R.layout.nav_menu_second_item, parent, false);
            holder = new ChildViewHolder();
            holder.name = (TextView) convertView.findViewById(R.id.menu_name);
            convertView.setTag(holder);
        }
        else{
            holder = (ChildViewHolder) convertView.getTag();
        }
        holder.name.setText(getChild(groupPosition,childPosition).sub_category_name);
        return convertView;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return false;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return mListDataHeader.size();
    }

    @Override
    public NavCategory getGroup(int groupPosition) {
        return navCategory;
    }

    @Override
    public int getGroupCount() {
        return 1;
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
                             View convertView, ViewGroup parent) {

        GroupViewHolder groupViewHolder;
        if (convertView == null) {
            LayoutInflater layoutInflater = (LayoutInflater) this.mContext
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = layoutInflater.inflate(R.layout.nav_menu_second_group_item, parent, false);
            groupViewHolder = new GroupViewHolder();
            groupViewHolder.name = (TextView) convertView.findViewById(R.id.menu_name);
            convertView.setTag(groupViewHolder);
        }
        else{
            groupViewHolder = (GroupViewHolder) convertView.getTag();
        }
        groupViewHolder.name.setText(getGroup(groupPosition).category_name);
        return convertView;
    }
}

final ExpandableListView secondLevelExpListView = new ExpandableListView(this.mContext);

final CustomExpandableListView customExpandableListView = new CustomExpandableListView(this.mContext);

public class CustomExpandableListView extends ExpandableListView {

    Context context;

    public CustomExpandableListView(Context _context)  {
        super(_context);
        context = _context;
    }

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)  {
        DisplayMetrics metrics = context.getResources().getDisplayMetrics();
        int screenWidth = (int)(metrics.widthPixels); //or whatever you need here for width of the row

        widthMeasureSpec = MeasureSpec.makeMeasureSpec(screenWidth, MeasureSpec.AT_MOST);
        heightMeasureSpec = MeasureSpec.makeMeasureSpec(20000, MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}